Project 4 is led by Dr. Trey Ideker and uses his cutting-edge approaches that evaluate GWAS results in a manner that takes into account biological networks. Specifically, these methods seek to identify sub-networks that have a dis-proportionate GWAS signal, even if none of the individual signals are genome-wide significant. Project 4 also uses network-based approaches to combine GWAS data from our center with human GWAS data to identify common biological networks that underlie SUD-relevant traits across species. These network-based approaches go beyond the single gene/linear effect models that are commonly used for GWAS, thus allowing us to assess the importance of higher order processes. Importantly, Project 4 uses GWAS results from Projects 1, 2, and 3 as well as GWAS results from several other affiliated grants, thus integrating data from across our center.